# Which Data Structure Is Used for Merge Sort?

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Larry Thompson

Merge sort is a popular sorting algorithm that utilizes a specific data structure called an array. Arrays play a crucial role in the implementation of merge sort as they allow for efficient splitting and merging of elements.

## The Array Data Structure

An array is a collection of elements of the same type, stored in contiguous memory locations. It provides random access to its elements, meaning that each element can be accessed directly using its index.

To understand how arrays are used in merge sort, let’s first take a look at the algorithm itself:

1. Divide the unsorted list into n sublists, each containing one element (base case).
2. Repeatedly merge sublists to produce new sorted sublists until there is only one sublist remaining.

The key step in merge sort is the merging of sublists. To efficiently merge two sorted sublists, we need to compare the elements from both lists and place them in order into a new resulting list. This is where arrays come into play.

## Merging with Arrays

When merging two sorted sublists using arrays, we create three additional arrays:

• Left array: stores the elements from the left sublist.
• Right array: stores the elements from the right sublist.
• Merged array: stores the merged result of both sublists.

We iterate through both the left and right arrays simultaneously, comparing their elements and placing them into the merged array in sorted order. This process continues until all elements have been merged into the resulting list.

Using arrays for merging allows for efficient comparison and placement of elements due to their random access property. We can directly access elements using their indices, making the merging process faster.

## Conclusion

In conclusion, merge sort is implemented using the array data structure. Arrays provide efficient splitting and merging of elements, which are essential steps in the merge sort algorithm. By utilizing arrays, merge sort achieves a time complexity of O(n log n), making it one of the most efficient sorting algorithms.

So next time you encounter a sorting problem that requires efficiency and performance, consider implementing merge sort with arrays to achieve optimal results!